audit: type=1800 audit(1588012002.164:1041): pid=1942 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=16425 res=0
xt_hashlimit: overflow, try lower: 0/0
overlayfs: failed to clone upperpath
MINIX-fs: mounting unchecked file system, running fsck is recommended
Process accounting resumed
BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: test_and_set_bit arch/x86/include/asm/bitops.h:220 [inline]
IP: test_and_set_bit_lock arch/x86/include/asm/bitops.h:233 [inline]
IP: trylock_buffer include/linux/buffer_head.h:367 [inline]
IP: lock_buffer include/linux/buffer_head.h:373 [inline]
IP: alloc_branch fs/minix/itree_common.c:88 [inline]
IP: get_block+0x6a7/0x10f0 fs/minix/itree_common.c:191
PGD 52514067 P4D 52514067 PUD a45f5067 PMD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 1942 Comm: syz-executor.4 Not tainted 4.14.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888092aa4100 task.stack: ffff8880432e8000
RIP: 0010:test_and_set_bit arch/x86/include/asm/bitops.h:220 [inline]
RIP: 0010:test_and_set_bit_lock arch/x86/include/asm/bitops.h:233 [inline]
RIP: 0010:trylock_buffer include/linux/buffer_head.h:367 [inline]
RIP: 0010:lock_buffer include/linux/buffer_head.h:373 [inline]
RIP: 0010:alloc_branch fs/minix/itree_common.c:88 [inline]
RIP: 0010:get_block+0x6a7/0x10f0 fs/minix/itree_common.c:191
RSP: 0018:ffff8880432ef5a8 EFLAGS: 00010246
RAX: 0000000000000007 RBX: ffff8880432ef6b0 RCX: 1ffffffff10279b4
RDX: 0000000000000000 RSI: ffffffff87d842e0 RDI: ffff888092aa4124
RBP: ffff8880432ef728 R08: 0000000000000001 R09: 0000000000000003
R10: ffff888092aa4a00 R11: ffff888092aa4100 R12: ffff8880432ef674
R13: ffff8880410e4ab0 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007ff229c35700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000003f1bc000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 minix_get_block+0xd6/0x100 fs/minix/inode.c:379
 __block_write_begin_int+0x337/0x1030 fs/buffer.c:2038
 __block_write_begin fs/buffer.c:2088 [inline]
 block_write_begin+0x58/0x260 fs/buffer.c:2147
 minix_write_begin+0x35/0xc0 fs/minix/inode.c:415
 generic_perform_write+0x1c9/0x420 mm/filemap.c:3047
 __generic_file_write_iter+0x227/0x590 mm/filemap.c:3172
 generic_file_write_iter+0x2fa/0x650 mm/filemap.c:3200
 call_write_iter include/linux/fs.h:1778 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x44e/0x630 fs/read_write.c:482
 __kernel_write+0xf5/0x330 fs/read_write.c:501
 do_acct_process+0xb49/0xf60 kernel/acct.c:520
 acct_pin_kill+0x28/0xe0 kernel/acct.c:174
 pin_kill+0x147/0x650 fs/fs_pin.c:50
 mnt_pin_kill+0x62/0x170 fs/fs_pin.c:87
 cleanup_mnt+0x110/0x140 fs/namespace.c:1180
 task_work_run+0x113/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1d6/0x220 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007ff229c34c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000509a40 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000500
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000c3e R14: 00000000004ce6bf R15: 00007ff229c356d4
Code: ca 08 00 00 49 8b bf 28 01 00 00 b9 08 00 00 00 e8 5f 04 c6 ff 31 d2 be 74 01 00 00 48 c7 c7 e0 f1 b9 86 49 89 c7 e8 e9 41 6d ff <f0> 41 0f ba 2f 02 0f 83 1f fe ff ff e8 88 2c 89 ff 4c 89 ff e8 
RIP: test_and_set_bit arch/x86/include/asm/bitops.h:220 [inline] RSP: ffff8880432ef5a8
RIP: test_and_set_bit_lock arch/x86/include/asm/bitops.h:233 [inline] RSP: ffff8880432ef5a8
RIP: trylock_buffer include/linux/buffer_head.h:367 [inline] RSP: ffff8880432ef5a8
RIP: lock_buffer include/linux/buffer_head.h:373 [inline] RSP: ffff8880432ef5a8
RIP: alloc_branch fs/minix/itree_common.c:88 [inline] RSP: ffff8880432ef5a8
RIP: get_block+0x6a7/0x10f0 fs/minix/itree_common.c:191 RSP: ffff8880432ef5a8
CR2: 0000000000000000
---[ end trace 56361337aca1b462 ]---